Conventionally, as a material of an absorbent article such as a disposable diaper and a sanitary napkin, liquid absorbent fibers such as pulp fibers and superabsorbent polymers (hereinbelow, referred to as SAP) and the like have been used.
Recently, from the viewpoint of recycling of resources, waste material such as defective articles of absorbent articles and defective articles of absorbent bodies are not disposed of as is, but the pulp fibers, the SAP and the like that can be recycled are collected from the waste material.
Regarding this point, PTL 1 discloses a device that separates and collects the pulp fibers and the SAP from the waste material in which the pulp fibers, the SAP and the like are mixed.
In more detail, this device has a case, and inside the case are housed three rotation members for opening fiber. Further, a ceiling section of the case is provided with an insertion port and a discharge port, and a lattice member is provided as a bottom section. The waste material is inserted from the insertion port into the case while riding on an airflow, and this waste material is opened with the above three rotation members. The pulp fibers of the waste material that have been opened ride on the airflow and are discharged from the discharge port and collected, and on the other hand the SAP and the like with a higher specific gravity than the pulp fibers are passed through openings of the lattice member that is the bottom section and dropped and collected.
Here, with this device, the rotation axis of each of the three rotation members is facing a direction (hereinafter, referred to also a left-right direction) that is orthogonal to a predetermined direction (hereinafter, also referred to as a front-rear direction) from the insertion port to the discharge port. Further, a peripheral surface of the rotation member has a rectangular plate row formed with a plurality of rectangular plates arranged in a row in a comb-form in a predetermined pitch in a direction along the rotation axis, and a plurality of rows of the comb-form rectangular plate rows are provided in a predetermined pitch in a circumferential direction of the rotation member.